T-Mobile’s Bobsled service, a VOIP-based communication platform that initially allowed smartphone owners to call their Facebook friends from their mobile device, has today been expanded to provide free calls to any mobile or landline number in the U.S, Canada or Puerto Rico from anywhere in the world, simply by using their desktop browser.

Whereas before, Bobsled would allow you to call Facebook friends from a dedicated smartphone application, the service has been adapted to give users the opportunity to call numbers in North America directly from the browser using their desktop computer and iOS or Android tablets or smartphones, taking aim at Google’s Voice service and Skype’s popular application that has recently been updated to include Facebook support across all platforms.

The ability to call numbers for free will tempt many, with both Skype and Google charging small amounts per minute for the ability to call mobile and landline numbers from their own applications and browser services.

To use Bobsled to call friends or family in America, Canada and Puerto Rico, users need to sign into the service (and also install relevant plugins), enabling the call, message or voice message options with their Facebook friends using their Mac or PC – all Facebook friends are loaded into the service automatically, requiring no physical dialling of numbers.

For mobile or landline calls, users need to dial a number using an Internet-connected browser on a supported device from anywhere in the world. Users can add mobile or landline numbers to their existing Facebook friends.

To download the application on your smartphone or tablet device, click this link for more information.